well ill say how i did all mine so far, but someone will probally say im doing it wrong and thats ok, but first of all i take a can of wd40 and spray the end of barrel and inside the trunion, then I put the end of the barrel with the muzzle break pointing down into a railroad tie and take a hammer and tap the trunion enough to get the barrel in enoughso it don't fall out, then i go over to my press and block up the rear sight block and us the press on the trunion, of course i have to stop when i get close to the barrel coming through and then switch to something smaller to drive it on through. Since i always have to basically do this stuff by my self it works out good for me, where as if i pressed from the other end, some help might be useful for that. For me it all seems to go in pretty easy if you lube it up real good before hand. Thats my 2 cents.